Immature Vascular Smooth Muscle Cells in Healthy Murine Arteries and Atherosclerotic Plaques: Localization and Activity

The local development of atherosclerotic lesions may, at least partly, be associated with the specific cellular composition of atherosclerosis-prone regions. Previously, it was demonstrated that a small population of immature vascular smooth muscle cells (VSMCs) expressing both CD146 and neuron-glial antigen 2 is postnatally sustained in atherosclerosis-prone sites. We supposed that these cells may be involved in atherogenesis and can continuously respond to angiotensin II, which is an atherogenic factor. Using immunohistochemistry, flow cytometry, wound migration assay xCELLigence system, and calcium imaging, we studied the functional activities of immature VSMCs in vitro and in vivo. According to our data, these cells do not express nestin, CD105, and the leptin receptor. They are localized in atherosclerosis-prone regions, and their number increases with age, from 5.7% to 23%. Immature VSMCs do not migrate to low shear stress areas and atherosclerotic lesions. They also do not have any unique response to angiotensin II. Thus, despite the localization of immature VSMCs and the presence of the link between their number and age, our study did not support the hypothesis that immature VSMCs are directly involved in the formation of atherosclerotic lesions. Additional lineage tracing studies can clarify the fate of these cells during atherogenesis.

3329Renal pathologic findings and clinical associations in patients with infective endocarditis

Background

Kidney involvement in infective endocarditis (IE) has a huge contribution in failure of the antimicrobal therapy and in rejection of the surgical treatment. Frequency of kidney lesions is still high and is diagnosed in 50–80% cases intravitaly, and in 91,6% post-mortem.

Materials/Methods

28 patients with verified IE (DUKE 2009, 2015), hospitalized and treated in clinical hospital from 2010 to 2018, were included in the study. Kidney function was assessed using CKD-EPI formula. Acute kidney injury (AKI) was diagnosed according to current guidelines (KDIGO 2012). Intravital nephrobiopsy was performed in 2 (7,1%) patients, in 26 patients (92,9%) morphological assessment was made on the autopsy tissue specimens. Autopsy material was assessed grossly and microscopically with H&E staining. Morphological changes in kidney were estimated based on standart histological criteria.

Results

Majority of patients with IE (92.9%) had structural changes in kidney tissue: 3 (12%), 16 (64%) and 6 (24%) patients had respectively isolated glomerular, tubular and mixed lesions. Significantly higher is rate of tubular lesion than glomerular (p=0.014). Main pattern in glomerular damage was mesangial proliferation, we didn't found any cases of crescentic GN. Herewith, proliferation was mainly diffuse (87.5%) rather than focal (12.5%). Glomerular damage in subacute IE (>56 days) appears more often than in acute IE (<56 days) (p=0.057 χ2=3.63). When studying the influence of various factors on the involvement of the glomeruli or tubules, no statistically significant group differences were obtained, except for the gram-negative flora as the causative agent, in which the tubules are significantly more likely to be affected (p=0.019)

Morphological diagnosis n (%) Morphological diagnosis n (%) Glomerulonephritis 8 (28.6) Tubulointerstitial nephritis 3 (10.7) Membranoproliferative glomerulonephritis 3 (10.7) Allegrgic tubulointerstitial nephritis 2 (7.2) Mesangioproliferative glomerulonephritis 5 (17.9) Infective tubulointerstitial nephritis 1 (3.6) Extracapillar crescentic glomerulonephritis 0 (0) Kidney abscess 3 (10.7) Acute tubular necrosis 22 (78.6) Kidney infarction 1 (3.6) Acute tubular necrosis (ischaemic) 11 (39.3) Renal artery embolism 1 (3.6) Acute tubular necrosis (toxic) 11 (39.3) Shock kidney 4 (14.3)

Conclusions

A morphological study of patients with IE revealed a wide range of kidney damage, however, the frequency of tubular lesions, mediated by nephrotoxic drugs and hemodynamic disorders significantly exceeds the frequency of immune complex glomerular lesions, as previously thought.

P2759Value of biomarkers (urinary KIM-1, NGAL, albumin, serum Cys C) for predicting renal lesions and prognosis in patients with infective endocarditis

Background

Infective endocarditis (IE) is frequently complicated by kidney damage of various pathogenesis. The essential differences in pathophysiological mechanisms of kidney lesions (glomerular and tubular damage, mixed mechanisms) create different therapeutical targets. Nowadays these mechanisms are only possible to differentiate with the use of nephrobiopsy or autopsy. Non-invasive methods to assess the genesis of kidney damage are eagerly wanted. It is possible that kidney biomarkers may be such method.

Materials and methods

209 patients with verified IE (DUKE 2009, 2015), hospitalized and treated in city clinical hospital named after V.V. Vinogradov in Moscow from January 2010 to June 2018, were included in the study. Kidney function was assessed using CKD-EPI formula. Acute kidney injury (AKI) and acute kidney disease (AKD) were diagnosed according to current guidelines (KDIGO 2012) and the work group consensus (ADQI 16 Workgroup 2017). Serum creatinine decrease on ≥26,5 mcmol/L in 48 hours after the hospitalization was counted as early-onset AKI. Patients with serum creatinine elevation on ≥26,5 mcmol/L in 48 hours during the hospitalization were diagnosed with late-onset AKI. Biomarkers were assessed at the admission. Cystatin C level was assessed in serum; neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule 1 (KIM-1), albumin levels were assessed in urine.

Results

Kidney damage biomarkers' levels were analyzed in 65 patients with IE. Patients with kidney dysfunction (n=45) comparing to ones without AKI (n=20) had higher mean value of all kidney biomarkers, however, the significant difference was established only for cystatin C. (1.9 vs 1.3 mg/l respectively; p<0.001). Patients with early-onset AKI (n=11) next to patients without AKI had significantly higher cystatin C value at admission (1.9 vs 1.3 mg/l respectively; p=0,0186). In similar manner patients with late-onset had had significantly higher cystatin C value at admission (1.9 vs 1.3 mg/l respectively; p=0,002). Cystatin C appeared to be an independent AKI predictor with threshold value 1.35 mg/l (OR 14.0; 95% CI 1.74–112.2; p=0.013), and also cystatin C was an independent predictor of the in-hospital mortality with threshold 1.87 mg/l (OR 3.16; 95% CI 1.25–7.99; p=0.006). After analysis of patients with AKD it was established that they had significantly higher levels of cystatin C (1.7 vs 1.3 mg/l respectively; p=0.035) and NGAL (19 vs 1.9 ng/ml; p=0.05) in comparison with patients without AKD. Albumin and KIM-1 didn't show significant associations.

Conclusions

The results of a study allow to consider serum cystatin C as AKI marker, AKI predictor and in-hospital mortality predictor in patients with IE, and urinal NGAL and serum cystatin C may be considered as AKD markers.

P2755Acute kidney injury risk calculator in patients with infective endocarditis

Background

Kidney involvement in IE has a huge contribution in failure of the treatment. Frequency of kidney lesions is still high. There are several risk calculators for prognosing embolic events, perioperational mortality, 6-month mortality, but there is none for prognosing kidney events in IE.

Materials/Methods

209 patients with verified IE (DUKE 2009, 2015), hospitalized from 2010 to 2018, were included in the study. Kidney function was assessed using CKD-EPI formula. AKI was diagnosed according to current guidelines (KDIGO 2012). Clinical, hematological and echocardiographic features were analysed to look for predictors of AKI. To create a simple risk calculator independent predictors obtained from log-regression analysis were used. The risk formula was derived using the coefficients: Pr(Y) = 1/[1 + exp(−XB)] where Pr(Y) = prognosed risk of AKI, XB = coef1*predictor1 + ... + logit-regression constant.

Results

AKI was presented in 66% cases and mainly was I (41%) and III (37%) stages. Predictors for AKI were established: MRSA OR 8.0 (95% CI 1.01–68.48; p=0.054), emergence or worsening of the HF sympthoms OR 2.83 (95% CI 1.27–6.32; p=0.011), gentamycin OR 2.71 (95% CI 1.33–5.53, p=0.006), history of CAD OR 2.35 (95% CI 1.05–5.27) p=0.038, WBC at admission >11.5x109/l OR 1.07 (95% CI 1.01–1.13), duration of hospitalization >20.7 days OR 1.03 (95% CI 1.01–1.05) p=0.005, C-reactive protein >90 mg/l OR 1.01 (95% CI 1.01–1.02) p=0.001.

Simple risk calculator Coef OR Indicator MRSA 2.0755 8 0 Emergence or worsening of the heart failure sympthoms 1.04041 2.83 0 Gentamycin 0.3640833 2.71 1 History of coronary artery disease 0.8542633 2.35 1 White blood count at admission 0.0691979 1.07 13 Duration of hospitalization 0.0308953 1.03 2 C-reactive protein 0.0075288 1.01 180 Constant −3.275098 0.0378132 Logit 0.259795900 P 0.564586119 Scaling parameter 100 Points 56 Result 56

Conclusions

A simple risk calculator for AKI is developed for patients with IE.

P829The impact of APOC3 and APOE gene polymorphisms on response to statin therapy in acute myocardial infarction

Background and aim

Many genetic studies have been reported about the association between APOE, APOC3 gene polymorphisms and response to statin therapy in myocardial infarction, but results remain controversial. The aim of this study was to investigate the association between SNP rs7412 (APOE), rs2854117 (APOC3), rs2854116 (APOC3) and lipid-lowering effect of atorvastatin and rosuvastatin in patients with myocardial infarction.

Methods

Polymorphism of genes APOE (rs7412), APOC3 (rs2854117 and rs2854116) was determened. Lipid profile was determined on admission and after 1 year of treatment.

Results

78 patients with myocardial infarction treated with maximal tolerated dose of atorvastatin or rosuvastatin were included. More pronounced reduction of lipid levels was associated with of T allele of rs7412 (APOE), p<0,05. ANOVA demonstrated greater low-density lipoprotein and total cholesterol decrease in patients with combination of genes CT/TT (rs7412, APOE) and CC (rs2854117, APOC3) genotypes, CT/TT (rs7412, APOE) and CT (rs2854116, APOC3) genotypes.

Conclusion

The genetic variants of APOC3 and APOE are useful markers and can be use to predict response to lipid-lowering therapy with statin in myocardial infarction.